WO2012168068A2

WO2012168068A2 - Vehicle heating unit and method for operating a vehicle heating unit

Info

Publication number: WO2012168068A2
Application number: PCT/EP2012/059483
Authority: WO
Inventors: Uwe Strecker; Luis Esteban
Original assignee: Webasto Ag
Priority date: 2011-06-10
Filing date: 2012-05-22
Publication date: 2012-12-13
Also published as: DE102011077437A1; WO2012168068A3

Abstract

The present invention relates to a vehicle heating unit (10) comprising an oxidation space (12), a feed device (14, 16, 18) for a substance which is to be fed to an oxidation process which takes place in the oxidation space (12) in order to generate heat, an optical sensor device (20) and a control unit (22) which is coupled to the optical sensor device (20), wherein the control unit (22) is configured to influence the oxidation process as a function of a signal which is generated by the optical sensor device (20) while the feed device (14, 16, 18) is operating, by changing an operating parameter of the feed device (14, 16, 18). The present invention also relates to a method for operating a vehicle heating unit.

Description

A vehicle heater and method of operating a vehicle heater

The present invention relates to a vehicle heater.

The invention further relates to a method for operating a vehicle heating device.

Vehicle heaters that generate heat from the oxidation of a liquid or gaseous fuel must have a sophisticated sensor to ensure a controlled low-emission conversion of the fuel. For example, sensors may be necessary to detect the temperature and exhaust gas composition. The present invention has for its object to provide a vehicle heater and a method for operating a vehicle heater, in which the necessary for the controlled implementation sensor can be simplified.

These objects are achieved with the features of the independent claims. Advantageous embodiments of the invention are specified in the dependent claims.

A vehicle heater is provided, comprising an oxidation space, a feed device for a substance to be supplied to an oxidation process taking place in the oxidation space, an optical sensor device and a control device coupled to the optical sensor device, wherein the control device is configured to control the oxidation process as a function of the signal generated by the optical sensor device during operation of the feeder by changing an operating parameter of the feeder. The phrase "during operation" means during a continuous supply of the substance, so that the operating parameter is changed in particular so that the feeder is not taken out of service and the supply of the substance is not stopped. Influencing is understood to mean, for example, controlling or regulating the feed device. When influencing the feed device, the control unit can determine, for example, a deviation of a signal generated by the optical flame detector from a reference signal stored in the control unit and influence the feed device based on the determined deviation in order to minimize the determined deviation. Alternatively or additionally, the control unit can influence the feed-in direction also evaluate a time derivative and / or a spatial derivative of the signal. Temporal and / or spatial maxima or minima of the signal may also be the basis for influencing the feeder and derived from the signal from the controller. The substance to be supplied may be, for example, fuel, oxidizing agent and recycled exhaust gas. Under fuel liquid or gaseous substances are understood, which can be oxidized together with an oxidizing agent with heat release. Fuels can be, for example, natural gas, gasoline or diesel. Oxidizing agent may be, for example, the oxygen contained in the air. The signal of the optical sensor device is understood to be the information transmitted by the optical sensor device to the control device. This information may include complex data, such as optical image data, wherein the image data may include data from a plurality of different pixels. The individual pixels may in particular include information about the brightness and the color. The optical sensor device can detect optical signals from the oxidation space, that is, in particular, a flame and / or objects that may be present in the oxidation space and walls delimiting the oxidation space. Spatially refers to separate pixels and a spatial distance can be understood as a distance between individual separate pixels of the image data. The reference signal is understood, for example, as information stored in the control unit, which may also comprise optical image data having a plurality of different pixels. The determination of a deviation can be understood to mean a difference between the detected optical image data of the generated signal and optical image data of the reference signal, which can be done pointwise, for example. For example, the acquired optical image data may comprise a single pixel whose color and brightness may be compared with the single optical pixel from the optical image data of the reference signal by subtraction. A feeder means a device for the controlled supply of a substance, for example fuel, oxidizing agent or recirculated exhaust gas. For example, the feed device may be a fan, a nozzle or a pump. By influencing the feeding device, it is possible, for example, to understand a change in the quantity of fuel, oxidizing agent or exhaust gas delivered by the feeding device per unit of time. The oxidation process can be, for example, a combustion process with a flame. Additionally or alternatively, the oxidation process may also include heat generation by means of flame-free catalytic oxidation of a fuel with an oxidant. The vehicle heater described allows a control of the oxidation process This is the fuel. By influencing the feed device, the oxidation process taking place in the vehicle heater, for example combustion, can be controlled. For example, deviations between the oxidation process currently taking place in the vehicle heater, which is characterized by the signal generated by the optical sensor device, and a desired oxidation process, which may be characterized, for example, by the reference signal stored in the control device, can follow the principle of a desired actual Regulation be reduced. The influencing of the oxidation process, for example its dynamic control, can be realized in the described vehicle heater advantageously via a single optical sensor device. Additional components, in particular other sensors, are not necessary. This allows a cost-effective realization of a controlled oxidation process in the described vehicle heater, through which, for example, the emission of pollutants can be reduced. Furthermore, it can be provided that the vehicle heater comprises a plurality of feed devices, and that the control device is adapted to at least one of the plurality of feeders in response to the signal generated by the optical sensor means during operation of the at least one of the plurality of feeders by changing an operating parameter of the at least one of the multiple feeders.

Usefully, it can be provided that the optical sensor device comprises an optical sensor which detects the oxidation space and / or a flame located in the oxidation space substantially completely optically. The essentially complete optical detection of the oxidation space and / or the flame possibly located in the oxidation space can enable a precise determination of the state of the oxidation process taking place in the oxidation space. It may be a prerequisite for a targeted influencing, for example a regulation of the ongoing oxidation process. Substantially complete detection means that optical signals from almost any point in the oxidation space can be detected by the optical sensor of the optical sensor device. An optical detection of the oxidation space also includes the optical detection of a body arranged in the oxidation space, for example a catalyst. Both the oxidation space and a body arranged in the oxidation space can act as a radiation source by their heating, for example by annealing with the delivery of optically detectable light. Furthermore, it can be provided that the optical sensor comprises a CCD sensor and / or a CMOS sensor. Both CCD and CMOS sensors are standard components for the detection of optical signals, each of which can be equipped with a different number of sensor surfaces for the detection of separate pixels. The use of such standardized components as an optical sensor can reduce the manufacturing cost of the vehicle heater described.

It can be provided that the optical sensor device comprises a glass fiber optic, which receives and forwards optical signals from the oxidation space. The glass fiber optics may comprise, for example, flexible light-conducting fibers, for example glass fibers. By using the glass fiber optic, the position of the optical sensor can be changed without changing the area optically detected by the sensor since the glass fiber optic picks up the existing optical signals and passes them on to the optical sensor. In this way, for example, the optical sensor can be disposed in a low-temperature region to lower the thermal noise of the optical sensor. Too high a thermal load can even lead to a failure of the optical sensor and is therefore essential to avoid. Furthermore, it can be provided that an inner circumferential surface enclosing the oxidation space has at least one opening, wherein the optical sensor device is arranged radially spaced from the at least one opening outside the oxidation space. This allows an arrangement of the optical sensor device outside the oxidation space. A direct optical detection of the oxidation space can be carried out by the simultaneously usable for supplying zuzuführendem substance, such as oxidizing agent and / or exhaust gas opening. The material to be fed in through the opening into the oxidation space shields the optical sensor device against high temperatures prevailing in the oxidation space and at the same time produces an effect which cools the optical sensor device. This can reduce the thermal noise of the used optical sensor, which increases with increasing temperature.

Alternatively it can be provided that the optical sensor device is arranged on an end face of the oxidation space. In particular, an input side of the oxidation space, which may be substantially closed or delimited, is referred to as the front side. Also in this way, the temperature may be limited, which is exposed to the optical sensor device during operation of the vehicle heater. All that Oxidation space supplied substances do not flow to the front side of the oxidation space but flow away from the front side of the oxidation space, so that a cooling convective heat transport takes place away from the optical sensor device. Usefully, it can be provided that the control unit is set up to end the operation of the feed device when the signal generated by the optical sensor device indicates an interruption of the oxidation process in the oxidation space. In this way, the optical sensor device can at the same time be used as the oxidation sensor, with the aid of which it can be determined whether the oxidation process is producing heat or whether it has been interrupted, for example.

Advantageously, it can be provided that the control unit is set up to actuate an ignition device when the signal generated by the optical sensor device indicates an interruption of the oxidation process in the oxidation space or an unstable oxidation process in the oxidation space. Actuation of the ignition device may help to stabilize an unstable oxidation process or prevent complete interruption of the oxidation process. For example, a complete extinction of the flame can be prevented or an accidentally extinguished flame can be re-ignited. In this way, in the vehicle heater described a cumbersome restart of the oxidation process, such as the combustion process can be prevented, so that the heat production of the vehicle heater described can be maintained safely even during a temporarily unstable oxidation process. An unstable oxidation process can be characterized, for example, by a signal of the optical sensor device that fluctuates temporally and rapidly fluctuating. The signal may then have periodically strong gradients, for example. Large spatial gradients between spaced pixels are also possible to characterize an unstable oxidation process. In this context, it may be provided that the control unit is set up to adjust the supply of the substance via the feed device to a predefinable start value if the signal generated by the optical sensor device indicates an interruption of the oxidation process in the oxidation space or an unstable oxidation process in the oxidation space , Thus, the described Fahrzeugheiz- device automatically advantageously the ongoing oxidation process, such as a combustion process or a flameless catalytic conversion of fuel and oxidizing agents, maintain and / or stabilize. For example, an unstable flame can be stabilized. An already extinguished flame can be re-ignited immediately and can be realized with the predefinable starting value without an escape of unburned fuel. This is analogous to a flame-free catalytic oxidation. This allows for continuous heat generation and low pollutant emissions by the vehicle heater. The predefinable starting value can be determined experimentally in advance, for example, and stored in a memory of the control unit. The starting value may designate a temperature-dependent stable operating point of the vehicle heater, wherein, for example, the temperature in the oxidation space and / or the temperature of the supplied substance may be taken into account, for example the oxidizing agent, the fuel and / or the recirculated exhaust gas.

Usefully, it can be provided that the substance to be supplied to the oxidation space comprises fuel, and that the control unit is set up to reduce the supply of fuel into the oxidation space if the signal generated by the optical sensor device indicates a yellowish coloration of a flame or too high Indicates temperature in the oxidation space. A yellowish color corresponds to an optical signal with an intensity maximum in the range of 575 to 585 nm wavelength. A yellowish color of a flame indicates a high proportion of soot particles in the flame, which shine yellow by thermal excitation. The oxidation process of the supplied fuel is incomplete. A reduction in the amount of fuel supplied can reduce the proportion of unburned soot particles in the flame, since the ratio of fuel and oxidant is shifted in favor of the oxidant. The oxidation process can then proceed more completely. By reducing the amount of fuel supplied, the heat released in the oxidation space per unit time, that is, the heat output of the vehicle heater, can be reduced, so that the temperature in the oxidation space can be reduced. The signal can also indicate the temperature of the oxidation space, for example in the case of a flame-free catalytic oxidation. The bodies arranged in the oxidation space and the surfaces delimiting the oxidation space can emit radiation, for example, which essentially determines the principle of the radiation of a black body. Therefore, for example, temperatures in the oxidation space can be determined from the radiation received by the optical sensor device, that is, the received radiation spectrum. For example, an orange glow may be associated with a first temperature Ti, while an orange glow may be associated with a second temperature Temperature T ₂ can be assigned and a yellow glow can be assigned to a third temperature T ₃ , where ΤΊ <T ₂ <T ₃ applies.

Furthermore, it can be provided that the substance to be supplied to the oxidation space comprises oxidizing agent, and that the control unit is set up to increase the supply of oxidizing agent into the oxidation space if the signal generated by the optical sensor device indicates a yellowish color of a flame. Additional oxidant may be added to react soot particles present in the flame to enhance the oxidation process of the fuel in the oxidation space. By improving the oxidation process in the vehicle heater, the amount of heat released in the vehicle heater per unit time can be increased slightly while reducing pollutant emissions of the vehicle heater in the form of soot at a constant supplied amount of fuel. It is also possible for the substance to be supplied to the oxidation space to comprise recirculated exhaust gas, and for the control unit to be arranged to reduce the recirculation of exhaust gas into the oxidation space if the signal generated by the optical sensor device is a yellowish color of a flame or too low Indicates temperature in the oxidation space. Recirculated exhaust gas is an inert gas for the oxidation process of fuel in the oxidation space, which can lower the reaction temperature and at the same time promote the formation of soot particles. Reducing the recirculated exhaust gas amount by influencing the feed device accordingly can therefore increase the temperature in the oxidation space and / or counteract a yellowish coloration of the flame.

The present invention also encompasses a method for operating a vehicle heating device comprising an oxidation space, a feed device for an oxidation process taking place in the oxidation space, an optical sensor device and a control device coupled to the optical sensor device, wherein the control unit controls the oxidation process as a function of the optical sensor device signal is influenced during operation of the feeder by changing an operating parameter of the feeder.

In particular, the method may use any vehicle heater as described herein. In this way, the advantages and particularities of beschriebnen vehicle heater are also implemented in the context of the described method.

The invention will now be described by way of example with reference to the accompanying drawings with reference to an embodiment.

Show it:

Figure 1 is a simplified sectional view of a vehicle heater;

Figure 2 is a simplified sectional view of another vehicle heater; and

3 shows a flow chart of a control circuit for influencing an oxidation process in a vehicle heater.

In the following description of the drawings, like reference characters designate like or similar components.

Figure 1 shows a simplified sectional view of a vehicle heater. The illustrated vehicle heater 10 includes a cylindrical oxidation space 12 having an inner circumferential surface 26. The oxidation space 12 may extend in an axial direction 60 and be configured, for example, as a combustion chamber. Furthermore, a first feed device 14, a second feed device 16 and a third feed device 18 are provided, with the aid of which fuel, oxidizing agent and combustion exhaust gases can be supplied to the oxidation space 12. The first feeder 14 may be coupled to a fuel line 38 for this purpose. The first feed device 14 can convey fuel from the fuel line 38 into the oxidation space 12 via a spray nozzle 36 projecting into the oxidation space 12. The first feeder 14 may be for example a metering device in the form of a metering pump for liquid fuel. Instead of the atomizing nozzle 36, a device for evaporating fuel known to the person skilled in the art, for example an evaporator fleece, may be arranged on an end face 64 of the oxidation space 12. Instead of the atomizing nozzle 36 for liquid fuels, a gas nozzle for gaseous fuels may be provided, in which case the first feeding device 14 may be designed, for example, as a throttle valve for gaseous fuel or between the first feeding device 14 and the gas nozzle a liquid fuel evaporator disposed can be. The second feeder 16 may be coupled to an oxidant line 40 and may deliver oxidant from the oxidant line via a clearance 44 into the oxidation space 12. The intermediate space 44 surrounds the inner circumferential surface 26 and is bounded in a radial direction 62 to the outside by an outer outer surface 58. The cross section of the intermediate space 44 can therefore be annular. The inner circumferential surface 26 has an opening 28 and further openings 48, via which, inter alia, the oxidizing agent from the intermediate space 44 can enter into the oxidation space 12. In the oxidation space 12, an at least partial mixing of supplied fuel and supplied oxidizing agent can take place, so that a combustible mixture comprising fuel and oxidizing agent can be formed. An ignition device 30, which may be embodied, for example, as a simple glow plug, may protrude, for example, starting from the end face 64 of the oxidation space 12 into the oxidation space 12. The ignition device 30 may be useful for igniting the combustible mixture comprising fuel and oxidizer. The ignition device 30 may be controllable in the usual manner by a control unit 22. By igniting the mixture comprising fuel and oxidant, a flame 32, which may have a flame front 34, can form in the oxidation space 12. A flameless oxidation process is also possible. At a side of the oxidation space 12 opposite to the atomizer nozzle 36, the exhaust gases produced during the oxidation process, for example combustion, can exit from the oxidation space 12. Part of the exhaust gases can be conveyed via an exhaust gas recirculation line 42 and the third supply means 18 into the intermediate space 44, from there again through the opening 28 and the other openings 48 to enter the oxidation space 12. The second feeder 16 and the third feeder 18 may be configured, for example, as simple blowers. As the oxidizing agent, for example, air can be used, wherein the oxygen contained in the air is reacted with the fuel. Accordingly, a mixture of oxidizing agent and exhaust gases may be present in the intermediate space 44. In addition to the openings 28, 48 explicitly illustrated in FIG. 1 in the inner lateral surface 26, there may be further openings (not explicitly shown) in the inner lateral surface 26. The passage of the mixture comprising oxidizing agent and exhaust gas from the intermediate space 44 into the oxidation space 12 can be influenced and optimized by a change in the arrangement and the size of the existing openings 28, 48 and the other openings (not shown). For example, the mixing with fuel and / or the shape and position of the possibly existing flame front 34 can be predetermined as required by adjusting the openings in advance. The first feeder Direction 14, the second feeder 16 and the third feeder 18 can be influenced by the control unit 22 via electrical lines 46. The influencing of the first feed device 14 and / or the second feed device 16 and / or the third feed device 18 can, for example, change one or more feed rates, that is to say one of the feed devices 14, 16, 18 per unit time delivered fuel, oxidizer or exhaust gas quantity. An optical sensor device 20 may be arranged in the radial direction 62 at a distance from the inner circumferential surface 26 at the outer surface 58 delimiting the gap 44. Alternatively, the optical sensor device 20 can also be arranged on the end face 64 of the oxidation chamber 12. The optical sensor device 20 can be coupled to the control device 22 via an electrical line 46 ', so that information determined by the optical sensor device 20 can be transmitted to the control device 22. The information determined by the optical sensor device 20 may include, for example, optical image data that may be acquired by means of an optical sensor 24 associated with the optical sensor device 20. The image data may comprise a single pixel or a plurality of pixels and may have information regarding brightness and color for each pixel. The optical sensor 24 may receive optical signals through the aperture 28 from the oxidation space 12, wherein the aperture 28 may act as a shutter. In this case, a viewing cone of the optical sensor 24 can be formed, which defines detectable regions of the oxidation space 12. This view cone is shown in Figure 1 by a boundary line 50 and another boundary line 52 abstract. In order to ensure a substantially complete detection of the oxidation space 12 by the optical sensor device 24, the sight cone can, for example, by changing the dimensions of the optical sensor 24 and the opening 28 and / or by changing the relative positioning of the optical sensor 24 to the opening 28 are changed. Furthermore, the optical sensor 24 may include a plurality of unrepresented independent optical sensor elements, which may be arranged spatially separated from each other. The plurality of optical sensor elements can be arranged, for example, radially spaced from openings in the inner circumferential surface 26, which are not identical to the opening 28. In this way, a plurality of optical sensor elements may be arranged behind a plurality of different openings in order to completely optically detect the oxidation space 12. The optical sensor 24 can detect optical information from the oxidation space 12, for example, directly or with the aid of a flexible fiberglass optics. The optical sensor 24 may include, for example, a CCD or a CMOS sensor, whereby, depending on the size and structure solution of the sensor used an optical detection of the oxidation chamber 12 in different resolution is possible. The resolution may be a single pixel or a plurality of pixels. For each pixel available, values for color and brightness or intensity may be provided. Two separate pixels have a spatial distance, so that spatial derivatives can also be determined from the image data. The spatial distance between two pixels corresponds to a real distance between two points in the oxidation space 12. The control unit 22 can receive the information detected by the optical sensor device 20 in the form of a signal. The signal may include image data. The control unit 22 can influence at least one of the feed devices 14, 16, 18 as a function of the received signal of the optical sensor device 20 during operation. In particular, the color encompassed by the signal can be taken into account in influencing. The control unit 22 can, for example, compare the received signal with a reference signal stored in the control unit 22. The reference signal, like the signal generated by the optical sensor device 20, may include image data. The reference signal may characterize a desired stable and low-emission operating condition of the vehicle heater 10, for example, depending on a desired heating power of the vehicle heater 10. The reference signal can be influenced, for example, by means of a control element 56 which is coupled to the control device 22 via a control line 54 and which can predefine a desired heating power of the vehicle heating device 10. This may allow complete control of the vehicle heater 10 via the optical sensor device 20. In particular, it can therefore be provided that the actuation of the operating element 56 only results in a change in the reference signal and does not directly influence the feed devices 14, 16, 18.

A comparison between the signal generated by the optical sensor device 20 and the reference signal stored in the control device 22 by the control device 22 can be effected, for example, by subtraction. Image data may be composed of values characterizing individual pixels, wherein each pixel may for example be associated with two independent values for color and intensity. It is also conceivable that the color channels for the pixels are separated. For example, in a cyan, a magenta and a yellow color channel. The difference between the generated signal and the reference signal can for example be pointwise. The reference signal stored in the control unit 22 may, for example, be a stable bluish-burning flame 32 with a clearly defined flame front 34 in the oxidant flame. onsraum 12 describe. If this deviates from a strongly flickering yellowish flame 32 with a correspondingly spatially migrating flame front 34, then the signal generated by the optical sensor device 20 will deviate greatly from the reference signal. In principle, for example, a color difference between individual pixels of the detected signal and the reference signal can be determined. By subtractive color mixing, for example, from the generated signal, which can represent a yellowish flame 32 in the oxidation space 12, the reference signal can be subtracted, which can represent a bluish flame 32 in the oxidation space 12. The deviation (or the distance) can be determined, for example, via the intensity of the remaining green components of individual pixels. Experimentally determined default values for influencing the individual feed devices 14, 16, 18 are possible. A large deviation between the two signals can, for example, lead to a greater influence on the first feed device 14 and / or the second feed device 16 and / or the third feed device 18, wherein, for example, the respective flow rate of the individual feed devices 14, 16, 18 increases as required or can be reduced. The detection of a yellowish flame, that is, the detection of yellowish light rays by the optical sensor 24 of the optical sensor device 20, for example, serve as a criterion for an incomplete oxidation process of the supplied fuel, wherein the incompletely burned fuel in the form of small soot particles in the yellow wavelength range Emit light. This light can be detected by the optical sensor 24. To reduce the soot particles, for example, the amount of fuel supplied can be reduced via the first supply device 14 and / or the amount of oxidizing agent supplied via the second supply device 16 can be increased and / or the amount of exhaust gas fed back via the third supply device 18 can be reduced.

An unstable operating state of the vehicle heating device 10 may be characterized, for example, by a rapidly changing signal, which may be the characteristic of a flickering flame 32. The optical sensor device 20 can temporally resolve this flickering due to its very short dead time. The flickering can be detected, for example, by subtraction of the image data in the case of two signals transmitted to the control unit in short time in succession. The small dead time of the optical sensor device 20 also permits a very rapid detection of the extinction of the flame 32 overall. If the signal of the optical sensor device 20 indicates an interruption of the oxidation process in the oxidation space 12, the control device 22 may be configured to end the supply of the substance via flow-fed feed devices 14, 16, 18. Thus, the optical sensor device 20 can also perform the function of a flame or oxidation monitor.

By using a plurality of separate optical sensor elements as part of the optical sensor 24, the flame 32 can be optically detected in the oxidation space 12 from different directions. In this way, a spatial detection of the flame front 34 of the flame 32 in the oxidation space 12 can take place, so that likewise a time-dependent displacement of the flame front 34, which can be, for example, periodic or quasi-periodic, can be detectable. Such spatial image data can also be compared as a generated signal with a stored reference signal and the deviation between the two signals used to influence the first feed device 14, the second feed device 16 and the third feed device 18 can be used.

The spatial migration of the flame front 34 over time can be an indication of an unstable operating state of the vehicle heater 10, which can be counteracted by a corresponding influencing of the first feed device 14 and / or the second feed device 16 and / or the third feed device 18. For this purpose, for example, the delivery rates of the first supply device 14 and / or the second supply device 16 and / or the third supply device 18 can be set to predefinable starting values, which can be experimentally known to characterize a stable operating state of the vehicle heating device 10.

The control unit 22 can be designed to refrain from influencing the first supply device 14, for example to minimize the determined deviation, if this leads to an increase in the amount of fuel supplied and at the same time the available fuel in the vehicle falls below a predeterminable minimum value. The fuel supply can be determined for example by a corresponding level sensor. By dispensing with the increase in the amount of fuel supplied fuel, a possible residual operating time of the vehicle heater 10 can be achieved by stretching the existing fuel supply. The control unit 22 can furthermore be designed to refrain from influencing at least one of the feed devices 14, 16, 18, which leads to an increased energy consumption of the feed device 14, 16, 18 when a determined operating voltage of a supplying vehicle battery falls below a predefinable threshold value. In this way, the power consumption of the vehicle heater 10 can be reduced, so that a possible remaining running time of the vehicle heater 10 can be increased.

Figure 2 shows a simplified sectional view of another vehicle heater. In contrast to the vehicle heater 10 known from FIG. 1, the vehicle heater 10 shown in FIG. 2 comprises an evaporator 66 for supplied fuel, which is arranged on the end face 64 of the oxidation space 12. Furthermore, a catalyst 68 may be arranged in the oxidation space 12 and at least partially fill it. In the illustrated vehicle heater 10, the oxidation process taking place in the oxidation space 12 may be flammable, wherein a catalytic conversion of supplied fuel and oxidant may take place essentially at the surface of the illustrated catalyst 68. The evaporator 66 may include an unspecified evaporator fleece. The fuel supplied to the evaporator fleece can be mixed with oxidizing agent in a manner known to those skilled in the art, which can be supplied, for example, via the openings 48 shown by way of example. Via the openings 48, recirculated exhaust gas can furthermore be supplied to the oxidation space 12. A flameless oxidation process may also be possible by suitable supply of recirculated exhaust gas without the catalyst 68. The optical sensor device 20 with the optical sensor 20 can be arranged on the end face 64 of the oxidation space 12 and comprise a glass fiber optic 70. The glass fiber optic 70 can receive optical signals from the oxidation space 12 and forward them to the optical sensor 24. By means of the glass fiber optics 70, the optical sensor 24 can be arranged at a greater distance from the oxidation space 12 without restricting the optically detectable area of the oxidation space 12. Thus, the evaporator 66 can occupy a larger area of the end face 62 of the oxidation space 12 and at the same time the temperature of the optical sensor 24 can be lowered. The optical sensor 24 can optically detect or perceive, in particular, the catalytic converter 68 and / or a section of the inner circumferential surface 26 of the oxidation space via the glass fiber optics 70. The provision of glass fiber optic 70 is optional. In operation of the illustrated vehicle heater 10, fuel supplied is reacted on the surface of the catalyst 68 while giving off heat with oxidant supplied. In this case, the catalyst 68 is heated strongly, so that it begins to glow. From the spectral composition of the optically perceivable annealing, the temperature of the catalyst 68 can be determined. The relationship between temperature and perceptible annealing may be that of a blackbody, with additional dependence on the material of the catalyst 68. In any case, an experimental determination of the relationship between the detectable spectrum and the temperature is possible. Since the temperature of the catalyst 68 is suitable as a size for influencing the feed devices 14, 16, 18, this applies likewise to the signal detectable by the optical sensor 24, so that the control device 22 is influenced based on an optical detection of the catalytic converter 68 the feed devices 14, 16, 18 can make. In the oxidation process, in addition to the catalyst 68, the inner circumferential surface 26 may be heated so that it also, for example, begins to glow. In an analogous manner, an optical detection of the annealing of the inner lateral surface 26 for influencing the feed devices 14, 16, 18 can therefore also be used, since their color is also related to the temperature of the oxidation chamber 12.

The basic operating principle of the vehicle heaters 10 described in FIGS. 1 and 2, that a signal generated by an optical sensor device is used to influence a feed device, is in principle also applicable to stationary heaters, internal combustion engines, gas turbines and other technical processes for detecting / influencing oxidation processes. applicable. One prerequisite, however, may be that heat is released which heats at least partially optically detectable body. FIG. 3 shows a flowchart of the control circuit for influencing an oxidation process in a vehicle heater. In step 100, data is collected. For example, image data can be determined optically by an optical sensor of an optical sensor device. The signal thus generated may therefore comprise, for example, image data. The image data may include individual pixels, each of which may be characterized by the necessary values for color and brightness. The individual pixels can optically detect the regions of the oxidation space of the vehicle heater that can be realized, for example, as a combustion chamber, from the optical sensor, with a specific predefinable resolution. The acquired data can be transmitted as a signal to the control unit of the vehicle heater. In step 102, the deviation of the detected data, that is to say the deviation of the detected signal, which may comprise image data, can be determined by a reference signal which may also include image data. The determination of the deviation can be done for example by the control unit of the vehicle heater. The determination of the deviation can be carried out, for example, with methods of image processing known to the person skilled in the art, which can be carried out by the control unit. The reference signal can be determined experimentally in advance and stored, for example, in a memory of the vehicle heater. The determination of the deviation can be done, for example, for each pixel individually by a difference between the values characterizing the respective pixel and the values representing the corresponding pixel in the reference signal. To simplify the calculation, the values characterizing the pixels can be averaged over several pixels, which corresponds to a low resolution. The reference signal may be adjusted in terms of the resolution of the image data included. The determined signal and the reference signal can also each comprise only a single pixel. The determined deviation can in turn comprise image data, which can be formed, for example, from the difference between the detected signal and the reference signal. According to the subtractive color mixing, the detected deviation may have a very low intensity if the detected signal is very similar to the reference signal. For example, the detected signal and the reference signal may each characterize bluish flames in the combustion chamber. The difference may then be very small, and the detected deviation may include image data that is substantially black, for example, because the bluish flame of the reference signal has canceled the bluish flame from the detected signal according to the subtractive color mixture. If, on the other hand, the detected signal characterizes a yellowish flame while the reference signal characterizes a bluish flame, the determined deviation can comprise, for example, image data which, according to the subtractive color mixture, characterizes a flame with strong green fractions. If necessary, step 102 can also be omitted and the influence can be determined directly from the signal determined.

The color of the image data can also be used to deduce the temperature of the imaged item. If, for example, the captured image data represent part of the oxidation space and / or the oxidation process takes place as a flameless conversion of fuel and oxidant, the temperature or the temperature distribution in the oxidation space can be determined by the detected colors and brightnesses in the image data. For example, a red glow of a temperature may correspond to Ti, while an orange glow may correspond to a temperature T ₂ and a yellow glow may correspond to a temperature T ₃ , where Ti <T ₂ <T ₃ . The exact temperatures are from the exact recorded color spectrum as well as the detected glowing material of the oxidation space dependent. An experimental determination of the exact relationship between the image data received by the optical sensor and the temperature can be carried out experimentally in advance, for example. The color of the image data can therefore also be used in a flameless oxidation for influencing the feed devices, for example for realizing a temperature control. Again, a deviation from a reference value can be determined and minimized. However, a direct influence based on the detected signal is also possible.

In step 104, one or more of the existing feeders of the vehicle heater may be affected according to the determined deviation. This can be done for example by the control unit of the vehicle heater. For example, no or only a very small influence on the feed devices can take place if the determined deviation comprises image data which essentially characterize a black image. On the other hand, if the determined deviation comprises image data which, for example, characterize a greenish flame, influencing of the feed devices can be carried out, for example, as a function of the average mean brightness of the flame characterized by the deviation. Depending on the desired heating power of the vehicle heater and the color and the averaged intensity of the determined deviation specifications for the delivery rates to be set individual or all feeders can be stored in a memory of the control unit of the vehicle heater. The values to be set, for example, may have been determined experimentally in advance. If step 102 is omitted, the influence of the feeders can also be made directly based on the received signal. For example, a time derivative of the signal or time minima and / or maxima can be determined and used. If, for example, the color and intensity of the signal is a measure of the temperature in the oxidation space, regulation of the temperature in the oxidation space can be realized. Instead of temporal changes of the image data and spatial changes can be considered, which can characterize, for example, the homogeneity of the oxidation process in the oxidation space.

The method may then be continued in step 100. This completes the control cycle associated with acquiring data from the oxidation space of the vehicle heater starts again. The method illustrated in FIG. 3 can be carried out by the vehicle heaters shown in FIGS. 1 and 2.

The method described can furthermore be used together with any oxidation processes in which heat is produced during the oxidation. For example, in stationary heating, internal combustion engines, gas turbines or in general, in technical processes for the detection and / or influence of oxidation states or processes.

The features of the invention disclosed in the foregoing description, in the drawings and in the claims may be essential to the realization of the invention both individually and in any combination.

LIST OF REFERENCE NUMBERS

10 vehicle heater

12 oxidation space

14 first feeder

16 second feeder

18 third feeder

20 optical sensor device

22 control unit

24 optical sensor

26 inner lateral surface

28 opening

30 ignition device

32 flame

34 flame front

36 atomizer nozzle

38 fuel line

40 oxidizer line

42 exhaust gas recirculation line

44 space

46 electrical line

46 'further electrical line

48 more openings

50 boundary line

52 additional boundary line

54 control line

56 control element

58 outer surface

60 axial direction

62 radial direction

64 front side

66 evaporator

68 catalyst

70 glass fiber optics 100 data capture

102 Determine deviation

104 influence metering device

Claims

claims

1 . Vehicle heating device (10) comprising an oxidation space (12), a feed device (14, 16, 18) for a substance to be supplied to an oxidation process taking place in the oxidation space (12), an optical sensor device (20) and an optical sensor device (20 ), wherein the control unit (22) is adapted to control the oxidation process as a function of a signal generated by the optical sensor device (20) during operation of the feed device (14, 16, 18) by changing an operating parameter of the feed device ( 14, 16, 18).

2. Vehicle heating device (10) according to claim 1, characterized in that the vehicle heating device (10) comprises a plurality of feed devices (14, 16, 18), and that the control device (22) is adapted to at least one of the plurality of feed devices (14, 16 18) as a function of the signal generated by the optical sensor device (20) during operation of the at least one of the plurality of feed devices (14, 16, 18) by changing an operating parameter of the at least one of the plurality of feed devices (14, 16, 18) to influence.

3. Vehicle heater (10) according to claim 1 or 2, characterized in that the optical sensor device (20) comprises an optical sensor (24), the oxidation space (12) and / or in the oxidation space (12) located flame (32 ) is detected substantially completely optically.

4. Vehicle heater (10) according to any one of the preceding claims, characterized in that the optical sensor (24) comprises a CCD sensor and / or a CMOS sensor.

5. Vehicle heater (10) according to any one of the preceding claims, characterized in that the optical sensor device (20) comprises a glass fiber optic (70) which receives optical signals from the oxidation space (12) and passes on.

6. The vehicle heater (10) according to any one of the preceding claims, character- ized in that an oxidation space (12) enveloping the inner circumferential surface (26) has at least one opening (28), wherein the optical sensor means (20) radially spaced from the at least an opening (28) outside of the oxidation space (12) is arranged.

7. Vehicle heating device (10) according to one of claims 1 to 5, characterized in that the optical sensor device (20) on a front side (64) of the oxidation onsraumes (12) is arranged.

8. A vehicle heating device (10) according to any one of the preceding claims, character- ized in that the control device (22) is adapted to terminate the operation of the feed device (14, 16, 18) when the of the optical sensor device (20). generated signal indicates an interruption of the oxidation process in the oxidation space (12).

9. Vehicle heating device (10) according to any one of the preceding claims, characterized in that the control device (22) is adapted to actuate an ignition device (30) when the signal generated by the optical sensor device (20) interrupting the oxidation process in the Oxidation space (12) or indicates an unstable oxidation process in the oxidation space (12).

10. Vehicle heating device (10) according to claim 9, characterized in that the control device (22) is adapted to adjust the supply of the substance via the feed device (14, 16, 18) to a predefinable start value, when the of the optical sensor device ( 20) indicates an interruption of the oxidation process in the oxidation space (12) or an unstable oxidation process in the oxidation space (12).

1 1. Vehicle heating device (10) according to any one of the preceding claims, characterized in that the substance to be supplied to the oxidation space (12) comprises fuel, and that the control device (22) is adapted to reduce the supply of fuel into the oxidation space (12) the signal generated by the optical sensor device (20) indicates a yellowish color of a flame (32) or indicates too high a temperature in the oxidation space (12).

12. The vehicle heater (10) according to any one of the preceding claims, character- ized in that the oxidation space (12) to be supplied material comprises oxidizing agent, and that the control unit (22) is adapted to the supply of oxidizing agent in the oxidation space (12). increase when the signal generated by the optical sensor device (20) indicates a yellowish color of a flame (32).

13. Vehicle heater (10) according to any one of the preceding claims, characterized in that the oxidation space (12) supplied substance comprises recirculated exhaust gas, and that the control unit (22) is adapted to the recirculation of exhaust gas in the oxidation space (12) reduce if the signal generated by the optical sensor device (20) indicates a yellowish color of a flame (32) or a too low temperature in the oxidation space (12).

14. A method for operating a vehicle heating device (10) comprising an oxidation space (12), a feed device (14, 16, 18) for a substance to be supplied in the oxidation space (12) oxidation process material, an optical sensor device (20) and a with the optical sensor device (20) coupled to control unit (22), wherein by the control unit (22) of the oxidation process in response to a signal generated by the optical sensor device (20) during operation of the feeder (14, 16, 18) by changing an operating parameter the feed device (14, 16, 18) is influenced.